Wire cutting apparatus

ABSTRACT

This is an invention for wire cutting apparatus. A drive shaft is coupled both to means for continuously feeding wire and rotating means for cutting and providing clearance for the continuously fed wire.

tlnited States Patent 1191 1111 3,783,726 Marks Jan. 8, 1974 [5 WIRECUTTING APPARATUS 2,570,466 10/1951 Macl-lenry 83/913 x 3,646,894 3/1972Hasten et al 83/355 X [75] Inventor: Marks Peabody Mass- 1,143,2856/1915 X66116 83/580 4/1955 Hoern 83/580 X [73] Asslgnee. InternationalTelephone and 2,707,026

Telegraph Corporation Nutley NJ 3,625,101 12/1971 Leveque 83/592 X [22]Filed: Mar. 19, 1973 Primary ExaminerAndrew R. Juhasz [21] Appl' 342336Assistant Examiner-James F. Coan Related US. Application DataAttorney-C. Cornell Remsen, Jr. et a1. [63] Continuation of Ser. No.147,097, May 26, 1971,

abandoned.

[52] US. Cl 83/355, 83/592, 83/913 ABSTRACT [51] Int. Cl B26d 5/22 [58]Field of Search 83/349, 355, 580, This is an invention for wire cuttingapparatus. A drive 83/591, 592, 913 shaft is coupled both to means forcontinuously feeding wire and rotating means for cutting and providing[56] References Cited clearance for the continuously fed wire.

UNITED STATES PATENTS 2,343,887 3/1944 Crane et a1. 83/592 xTSQTIEThwADraWgTT EE 86 88 e6 3 a a 7 1; 'u w w v w 11 PATENTEU INVENTORJOHN L. MAHMS ATTORNEY l WIRE CUTTING APPARATUS This is a continuationof application Ser. No. 147,097, filed May 26, 1971, and now abandoned.

BACKGROUND OF THE INVENTION and extends somewhat past the hole. Thus, ifthe wire being cut would be continuously fed through the hole in thedie, it would be propelled into the reciprocating cutter blade, thusjamming the machine. In order to avoid such jamming, the wire is notcontinuously fed, but instead, the wire feed is halted as each wire isbeing cut in order to allow time for the reciprocating cutter blade tobe raised and allow clearance for the feed wire. Therefore, by haltingthe wire feed as each wire is being cut, the reciprocating wire cuttingmachine places a definite limit on the speed of cutting these wires andthus, a definite limit on the production of the wire leads. Of course,the smaller the wire to be cut the longer is the period of time-when thewire feed itself will be shut down.

It has been found that wire of the order of 50 mm in length can only becut at speeds of approximately 80 to 125 pieces per minute usingreciprocating cutting machines. Furthermore, this type of machinerequires considerable skill for .its operation.

SUMMARY OF THE INVENTION It is therefore an object of this invention toprovide a wire cutting machine requiring less skill for its operation.

It is a further object of this invention to provide a 'wire cuttingmachine operating at speeds greatly in excess of the speed of areciprocating cutting machine.

It is a still further object of this invention to provide for a wirecutting machine having a continuous wire feed. I

According to a broad aspect of this invention, there is provided a wirecutting apparatus comprising rotational drive means, means coupled tosaid drive means for continuously feeding wire to be cut and rotatingmeans coupled to said drive means for cutting and providing clearancefor the continuously fed wire.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the wire assembly;

FIG. 2 is a top view of the wire cutting apparatus;

FIG. 3 is a sectional view of the cutting apparatus taken along plane XXshown in FIG. 2; and

FIG. 4 is a top view of the disk cutter.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The wire cutting apparatus inthis embodiment is used to manufacture filaments for incandescent lampsor electrodes for fluorescent lamps but, of course, is not confined tothe manufacture of these products, and can be used to cut any shortwires of accurate length.

FIG. ll shows tungsten wire 1 wound around a mandrel 2 which may consistof metal such as steel or molybdenum. The thickness of the overallassembly in this example is in the order of 0.010 inches. The winding iswrapped around the mandrel and then subjected to a deforming processwhich generally consists of strain annealing in a controlled hydrogenatmosphere. This continuous wound tungsten filament is reduced to shortuniform lengths using our wire cutting apparatus, after which cuttingoperation the mandrel is removed, usually by etching in an acid.

The top view of the wire cutting machine is shown in FIG. 2, whereinconstant speed motor 3 drives shaft 4. Pulleys 5 and 6 coupled togetherby belt 7 are used to rotate the drive shaft 8 at a reduced rotationalspeed with respect to shaft 2. In this example, motor 3 rotates shaft 4at 3,700 rpm and the pulley arrangement rotates drive shaft 8 at 1,500rpm, the speed reduction being provided by suitably selected pulleys.Drive shaft 8 is directly connected to a gear train assembly 0 andspecifically to input gear l0. An output gear ill is then used to driveshaft 12 at a reduced rotational speed with respect to drive shaft 8,which reduced speed is determined by the final gear reduction ratio ofgear train 9. The gear train having the desired reduction ratio caneither be purchased or assembled using appropriate sized gears. Shaft 12is attached to a drum 13 by use of suitable set screws in portion M- ofdrum 13. In this example, the drum is made of standard machine steel.Drum 13 engages the wire assembly W which consists of mandrel 2 andwound filament 1 and propells the assembly through a hole 15 in a die16, which die rests within a support 17. The wire assembly W exits theopposite end of hole 15 in a continuously fed fashion where it is cut bythe cutter assembly. Thus the continuous feed means consists of the geartrain assembly 9 which is connected to drive shaft 8, drum 13 which isconnected to the output of the gear train via shaft 12, and the support17 which holds die 16. The wire assembly is cut at the rate of therotational speed of shaft 0, which shaft is attached via suitable setscrews to cutter holder 10. Cutter holder 118 has a cylindrical shapeand a flat surface portion 19 which extends outward in a flange-likemanner. Cutter blade 20 in this example is a disk-shaped cutter and isattached to the flat surface portion 119 of cutter holder 10 using asuitable fastening arrangement.

A sectional view of FIG. 2 along plane XX is shown in FIG. 3 where thecutter is in the rotational position for cutting wire assembly W. Thewire is fed to drum 13 via a suitable standard spool feed. Rubberrollers 21 and 22 are shown pressing the wire assembly'against drum 13so as to enable drum R3 to propel wire W through hole in support jacket16. Rollers 2i and 22 were not shown in FIG. 2 for purposes of clarity.Support jacket or die 16 is made of steel in this example and isapproximately 1% inches long and approximately 0.312 inch in diameter.Jacket 16 has a die 23 placed therein to narrow the feed hole for thewire assembly to about 0.075 inch and to provide support and a cuttingedge for the wire as it engages the cutter blade 20. Die 23 and cutterblade 20 in this example are both made of a tungsten-carbon alloy, knownin the trade as Grade 55B Carboloy. It should be noted that while theadjacent edge 24lof die 23 is perpendicular to the axis of hole 15 foran approximate distance of 1/64 of an inch from hole 15, thereafter, theremainder 25 of that surface tapers from the plane of edge 24 atapproximately 2V2 in the direction away from cutter blade 20 so as toprovide some clearance for the rotating cutter blade. It should also benoted that the cutter blade in this example has a bevelled edge 26,which edge has an angle G greater than 60 with the plane of the surface27 of cutter blade 20. The bevelled edge 26 serves to provide clearancefor cutter blade 20 as it rotates past die 23. When blade 20 begins tocut wire assembly W, the flat surface portion 19 of cutter holder 18 andthe plane 27 of cutter 20 makes an angle of approximately 30 with thehorizontal axis. The angle can be adjusted to provide maximum cuttingforce for the cutter while also providing sufficient clearance for thecontinuously fed wire so that no portion of the rotating cutter bladecomes in contact with the wire assembly until the cutter is in positionto actually cut the wire. The length of the cut wire actually isdetermined by the formula where L length of wire in millimeters;

D diameter of the drum in inches;

R the gear train ratio; and

K is a conversion factor equal to 25.4 for converting inches tomillimeters. In this example, with R equalling l and D equalling 6.25,the length of wire to be cut equals 50 mm. From the above formula, itcan be seen that by varying the diameter of the drum 13 or the ratio ofthe gear train 9, the length of cut wire could be varied. However, thelargest length of wire which can be cut is limited since there is apoint beyond which the continuously fed wire will prematurely interferewith some portion of the rotating cutter blade 20, and when the angle ofthe surface portion 19 and disk plane 27 with respect to the horizontalaxis is 30, the maximum length of wire which could be cut isapproximately 60 mm. By reducing the angle of surface portion 19 anddisk plane 27 with respect to the horizontal axis to approximately 20,the maximum length of cut wire could be extended to approximately 70 mm.After which point, if longer wire sections are required, it might benecessary to remove portions of blade 20 to provide for additionalclearance.

Circular blade 20 as shown in FIG. 4 in this example is approximately 17/16 inches in diameter and approximately 0.067 inches thick. Also, inthis example, cutter holder 18 is approximately 1% inches in diameterand has a 3/4 inch hole therein so as to fit around shaft 8. Actually,cutter blade 20 should be so mounted on cutter holder 18 that the outermost tip of the cutter blade will engage the wire assembly just as itleaves hole 15 so that the cutter will clear the die and still cleanlycut the wire. In this particular example, the axis of the cutter holderis horizontally aligned with the axis of the wire to be cut, and thisaxis is approximately 1% inches from the point where the wire will becut and the cutter blade 20 is so positioned on the cutter holder 18 toaccomplish this purpose. It should also be noted that except for theextended portion 28 of cutter holder 18,

the remaining portions of holder 18 are not in line with and will notinterfere with the continuously fed wire. it

should further be noted that the extended portion 28 of 5 cutter holder18 serves the purpose of providing balanced mechanical support forcutter blade 20.

The apparatus, in this example, is cutting the wire sections at a rateof 1,500 pieces per minute, and can satisfactorily operate at a rate of3,000 pieces per minute. Thus the apparatus satisfactorily operates atmore than to 20 times the cutting rate of reciprocating type cuttingmachines.

It is to be understood that the foregoing description of specificexamples of this invention is made by way of example only and is not tobe considered as a limitation on its scope.

I claim:

1. A wire cutting apparatus, comprising:

rotational drive means;

means coupled to said drive means for continuously feeding at asubstantially constant rate wire to be cut;

support means having an aperture through which said wire is fed forproviding a base support when said wire is cut;

rotating means mounted on said apparatus to rotate in a planesubstantially parallel with the axis of said aperture;

means for coupling said drive means to rotate said rotating means forcutting said wire as it exits from said aperture and providing clearancefor the continuously fed wire by rotating out of the path of said wire,said rotating means including a substantially cylindrical cutter holder;and

a disk shaped cutter blade having a bevelled edge and mounted on saidholder to impinge against said wire at the exit of said aperture.

2. An apparatus according to claim 1, wherein said drive means includesa drive shaft coupled to said con- 40 tinuously feeding means androtating cutting means.

3. An apparatus according to claim 2, wherein said continuous feed meansfurther includes:

a gear train having an input and output, the input of said gear trainbeing coupled to said drive shaft;

a rotating drum for engaging the wire to be cut and for propelling thewire through aperture in said support, said drum being coupled to theoutput of said gear train; and

first and second rollers for pressing said wire against said rotatingdrum.

4. An apparatus according to claim 1, wherein during the course of onerevolution of said cutter the outermost portion of said bevelled edge ispositioned adjacent the aperture in said support to engage and cut saidwire as it leaves the aperture, the plane of said disk being at an angleof greater than 20 with the axis of the aperture in said support.

5. An apparatus according to claim 4, wherein said angle is 30.

1. A wire cutting apparatus, comprising: rotational drive means; meanscoupled to said drive means for continuously feeding at a substantiallyconstant rate wire to be cut; support means having an aperture throughwhich said wire is fed for providing a base support when said wire iscut; rotating means mounted on sAid apparatus to rotate in a planesubstantially parallel with the axis of said aperture; means forcoupling said drive means to rotate said rotating means for cutting saidwire as it exits from said aperture and providing clearance for thecontinuously fed wire by rotating out of the path of said wire, saidrotating means including a substantially cylindrical cutter holder; anda disk shaped cutter blade having a bevelled edge and mounted on saidholder to impinge against said wire at the exit of said aperture.
 2. Anapparatus according to claim 1, wherein said drive means includes adrive shaft coupled to said continuously feeding means and rotatingcutting means.
 3. An apparatus according to claim 2, wherein saidcontinuous feed means further includes: a gear train having an input andoutput, the input of said gear train being coupled to said drive shaft;a rotating drum for engaging the wire to be cut and for propelling thewire through aperture in said support, said drum being coupled to theoutput of said gear train; and first and second rollers for pressingsaid wire against said rotating drum.
 4. An apparatus according to claim1, wherein during the course of one revolution of said cutter theoutermost portion of said bevelled edge is positioned adjacent theaperture in said support to engage and cut said wire as it leaves theaperture, the plane of said disk being at an angle of greater than 20*with the axis of the aperture in said support.
 5. An apparatus accordingto claim 4, wherein said angle is 30* .